Difference between revisions of "Team:FJNU-China/Demonstrate"
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| − | <div id="Part3"> <h2 style="text-shadow: 0 0 20px | + | <div id="Part3"> <h2 style="text-shadow: 0 0 20px purple;">Part3: Prove the practical feasibility of our products.</h2> </div> |
<p> This year, the main focus of our project was to prevent harmful bacteria in the laboratory waste beaker and to solve its odor problem. In addition, we designed a waste beaker cover to better achieve this goal. In order to verify the practical feasibility of our products, we applied this waste beaker cover to our laboratory to test its function.</br> | <p> This year, the main focus of our project was to prevent harmful bacteria in the laboratory waste beaker and to solve its odor problem. In addition, we designed a waste beaker cover to better achieve this goal. In order to verify the practical feasibility of our products, we applied this waste beaker cover to our laboratory to test its function.</br> | ||
We set up a set of contrast experiments using two beakers in the lab. The beaker contains the experimental waste produced by our usual experiments, including the pipette tip, the paper scraps, the discarded tubes, and so on. We applied our cover to one of the beakers and pressed the red button to release our engineered bacteria to produce rose-scented bacteriostat, and the other beaker was left untreated as a control. We exposed them to the same environment.</br> | We set up a set of contrast experiments using two beakers in the lab. The beaker contains the experimental waste produced by our usual experiments, including the pipette tip, the paper scraps, the discarded tubes, and so on. We applied our cover to one of the beakers and pressed the red button to release our engineered bacteria to produce rose-scented bacteriostat, and the other beaker was left untreated as a control. We exposed them to the same environment.</br> | ||
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| − | <div id="Part4"> <h2 style="text-shadow: 0 0 20px | + | <div id="Part4"> <h2 style="text-shadow: 0 0 20px yellow;">Part4: Prove the practical feasibility of our products.</h2> </div> |
<p> On the other hand, we conducted a survey of similar products on the market to better demonstrate the advantages of our products, trying to compare some of the antibacterial products in the domestic market with our rose-scented bacteriostat.</br> | <p> On the other hand, we conducted a survey of similar products on the market to better demonstrate the advantages of our products, trying to compare some of the antibacterial products in the domestic market with our rose-scented bacteriostat.</br> | ||
We chose a hand sanitizer product with a fresh fragrance and a representative soap as a control. We firstly prepared 10mmol/l of PLA and took 5 grams of two market products into 45g of sterile water to dissolution. After we exposed the prepared plate to the laboratory for 12 hours, we added 100 ul of three products prepared in advance on the surface. They were observed after 12 hours of incubation in the same environment. | We chose a hand sanitizer product with a fresh fragrance and a representative soap as a control. We firstly prepared 10mmol/l of PLA and took 5 grams of two market products into 45g of sterile water to dissolution. After we exposed the prepared plate to the laboratory for 12 hours, we added 100 ul of three products prepared in advance on the surface. They were observed after 12 hours of incubation in the same environment. | ||
Revision as of 05:46, 17 October 2018
Demonstrate
Overview
This year, our team focused on solving the problems causing from harmful bacteria and bad smells in everyday life. Through the method of synthetic biology, we successfully produced phenyllaclic acid (PLA) with broad spectrum bacteriostatic function and rose-aromatic compound 2-phenyl alcohol (2-PE), and hoped to apply it to the urgent needs of human beings. Our project inspired us to propose some specific applications of our rose-scented bacteriostat, including in waste beaker in the lab and axilla. We believe that our work has reached the medal requirements of demonstration as we have confirmed the function of PLA and 2-PE and made sure our system can produce those two things. In addition, we also have demonstrated our waste beaker cover in the laboratory to prove the practical feasibility of our products. The details of the demonstration are shown below. You can learn more details of the experiment and results in our design and results, modeling page.
Part1
Validation of Broad spectrum antibacterial function of PLA
Part2
Practicability and Mechanism of PLA
Part3
Prove the practical feasibility of our products
Part4
Demonstrate the advantages of our products
Part1: Validation of Broad spectrum antibacterial function of PLA
We used a certain concentration of PLA to effect on a variety of bacteria, and measured the residual amounts of bacteria over time to verify the broad spectrum antibacterial properties of PLA. Because of the limited strain of our laboratory，we completed this part in cooperation with other teams. We measured the inhibition effect of PLA on yeast Cen.PK2-1C, Staphylococcus aureus, Pseudomonas aeruginosa , yeast Cen.PK2-1D and other bacteria respectively（For details, please read the collaboration page）. The collective data figure is as follows.
Fig.1 Growth of different initial value of OD Cen.PK2-1D under 16mMol/L PLA
Fig.2 Growth of different initial value of OD Cen.PK2-1C under 16mMol/L PLA
From the above data, we can clearly see that PLA can inhibit the growth of most bacteria, which directly proves its broad-spectrum antibacterial properties.
Part2: Practicability and Mechanism of PLA
Phenylalanine is converted to phenylpyruvate by the action of an aminotransferase (Tyrb) from Escherichia coli 21B, which is then dehydrogenated by lactate dehydrogenase (D-ldh) to form phenyllactic acid (PLA). Through the above experimental methods in part1, we simply qualitative analysis of PLA antimicrobial effect, and in the follows we further quantitatively verify the antimicrobial effect and practicability of PLA through modeling and experiment. And in this part, we also have found the mechanism of PLA and verify it（For details, please see the Model page）.
（1）Quantitative Validation of bacteriostatic effect of PLA
We used different concentrations of PLA to react with Staphylococcus epidermidis with different initial value of OD, and we measured the bacterial residue every hour and obtained the following formulas and diagrams.
Fig.3 Simulation of the number of bacteria colonies under different concentrations of PLA.
Staphylococcus epidermidis is the main cause of armpit odor. From the above chart we can see that PLA has an effective inhibiting effect on Staphylococcus epidermidis, and the higher the concentration of PLA, the better the inhibition effect, which quantitatively proves the effectiveness of PLA and the practical feasibility of the products we used to treat armpit odor.
（2）Timeliness of PLA inhibition effect
We used different concentrations of PLA to react with Staphylococcus epidermidis with different initial value of OD, and we measured the bacterial residue every hour and obtained the following formulas and diagrams.
Fig.4 Growth of staphylococcus epidermidis with an initial OD value of 1 under 11.25mmol/L of PLA
In addition, we calculated the lowest optimum PLA concentration to inhibit Staphylococcus epidermidis, at which the growth rate of bacteria was always lower than the mortality rate. When PLA is higher than this concentration, the reaction rate will be faster.
（3）Validation of the breadth applicability of specific PLA concentration（Mechanism of PLA）
Fig.5 Growth of staphylococcus epidermidis with an initial OD value of 0.5Abs under different concentrations of PLA
Fig.6 Growth of staphylococcus epidermidis with an initial OD value of 2Abs under different concentrations of PLA
Through these two figures, we learned that the effect of PLA in inhibiting the bacteria is independent to the initial OD value，which means the certain amount of PLA have the same inhibiting effect on the different amount of bacteria. The above analysis told us that under the same concentration of PLA, the number of strains inhibited by PLA is in proportion to the total number of current strains. Therefore, PLA is killing bacteria according to the proportion of bacteria，which also means that the data obtained by the above model are suitable for any number of Staphylococcus epidermidis.
Part3: Prove the practical feasibility of our products.
This year, the main focus of our project was to prevent harmful bacteria in the laboratory waste beaker and to solve its odor problem. In addition, we designed a waste beaker cover to better achieve this goal. In order to verify the practical feasibility of our products, we applied this waste beaker cover to our laboratory to test its function. We set up a set of contrast experiments using two beakers in the lab. The beaker contains the experimental waste produced by our usual experiments, including the pipette tip, the paper scraps, the discarded tubes, and so on. We applied our cover to one of the beakers and pressed the red button to release our engineered bacteria to produce rose-scented bacteriostat, and the other beaker was left untreated as a control. We exposed them to the same environment. After 24 hours, they had subtle differences. And we observed a more obvious comparison (as the figure shown) after 3 days. In the natural environment, the untreated beaker was filled with white colonies; on the contrary, there is less bacteria in the beaker with PLA. Regarding the odor contrast, the beaker of the blank control gave off bad smells, while the other beaker showed a noticeable improvement with a faint rose scent.
To summary, we have demonstrated our design in the laboratory, which proves that our antibacterial and aroma substances can solve the harmful bacteria and odors in the experiment more effectively.
Part4: Prove the practical feasibility of our products.
On the other hand, we conducted a survey of similar products on the market to better demonstrate the advantages of our products, trying to compare some of the antibacterial products in the domestic market with our rose-scented bacteriostat. We chose a hand sanitizer product with a fresh fragrance and a representative soap as a control. We firstly prepared 10mmol/l of PLA and took 5 grams of two market products into 45g of sterile water to dissolution. After we exposed the prepared plate to the laboratory for 12 hours, we added 100 ul of three products prepared in advance on the surface. They were observed after 12 hours of incubation in the same environment.
The No. 1 plate showed the growth of the bacteria under normal conditions. The No. 2 plate was treated with soap, and the third was treated with hand sanitizer, and the No. 4 board was coated with our rose-scented bacteriostat. As shown in the figure, we can clearly see that the number of colonies on the No.2, No.3, and No.4 plates is reduced compared to the No. 1 plate. Among them, the soap of such brand has a relatively weaker antibacterial effect than the other two products. And the hand sanitizer is equivalent to our antibacterial and aroma-producing substances. Our rose-scented bacteriostatic and the hand sanitizer have comparable bacteriostatic effects. In addition, we use synthetic biology to produce such rose-scented bacteriostatic, reducing the burden on the environment and being safer and more friendly to people. To conclude, we have demonstrated the advantages of our products to better address people's needs and environmental issues in daily life.
Reference
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